Wish you had a dollar for every time a cold front or a thunderstorm in your area caused your favorite lake's Florida-strain largemouth bass to develop lockjaw? By now we've realized that it happens because Florida-strain largemouth are more affected by weather changes and drops in water temperature than Northern-strain largemouth are even in summer. But in late spring/early summer, before the water temperature has stabilized, they can seem especially temperamental.